GENERAL BACKGROUND

In the fabrication world, CNC (computer numerical control) machines have been around for more than 50 years. Over that time, the term “CNC” has been adopted as a shorthand reference to milling or routing, where a spinning end mill removes material to engrave, cut shapes out of flat stock, or carve intricate 3D designs from thick materials.

One of the many reasons CNC mills are so important to Fab Lab is that they provide an easy way to precisely produce complex physical parts for almost every project type imaginable. The CNC moniker means that the instructions that control the machine and toolpath are preprogrammed into code. It ensures that the 100th part produced is identical to the first.

PROCESS

Like 3D printers, which use CNC to control movement of an extruder head, the majority of CNC mills are 3-axis machines that move the toolhead through a piece of stock material. Some function by moving just the spindle, others move the bed, and some move both the spindle and the bed, depending on the axis.

A CNC mill allows you to quickly and accurately work with harder materials that are not normally possible with other technologies. These can vary from hard and soft woods, laminates like plywood, plastics of any kind, and hard and soft metals. The only limitation to what you can cut is the scale and rigidity of the machine and the end mill being used.

The hardness of the material being cut and the size of the end mill makes correct setting of these instructions crucial. Too fast a setting can result in broken bits. Too slow and you risk burning your material.

Due to the wide variety of possible geometries and applications members are required to provide their own end mills and cutting tools.